HP Autowerks lightweight battery kit installed - 30lbs lighter

[BerkTechnology]

Even with all of the electrical gizzmo's that the BMW has we haven't had any hiccups with the installation and use of the smaller battery. We'll report back if someone bumps this thread. So far so good!

[HP Autosport]

Originally Posted by BerkTechnology

Even with all of the electrical gizzmo's that the BMW has we haven't had any hiccups with the installation and use of the smaller battery. We'll report back if someone bumps this thread. So far so good!

Let us know how the battery performs over the race weekend!

[Mega Man]

BerkTechnology, as always, I love reading these updates on your ultimate driving machine.

Wish I had the resources and passion available to me to do this with my car.

[HP Autosport]

Anymore feedback on our lightweight battery kit?

[BerkTechnology]

Originally Posted by Mega Man

BerkTechnology, as always, I love reading these updates on your ultimate driving machine.

Wish I had the resources and passion available to me to do this with my car.

Update from the last race weekend. We absolutely murdered the standing record for a 135i at Willow Springs Raceway. Loosing 30lbs in the rear with the HP Autowerks battery kit and the 100 other things all have their own small part of it!

1.34.241 - Berk Technology/Dunlop Tire - NEW RECORD

[stylinexpat]

Any other good lightweight batteries out there for the 135i? Losing 20Lbs. would nice and enough.

[J Tyler]

Originally Posted by akak1997

Also, how does lighter weight in the rear give more grip at the rear? I always thought if you've less weight in the rear, you get less grip. That's why pickup trucks put water barrel on their bed during winter time.

Thanks

No. There is a reason why F1 teams spend hundreds of millions of dollars to make the cars as light as possible. There is a reason why race cars are lighter than street cars.

Imagine a small weight tied to the end of a string. Take the string and twirl it around in the air. The bigger the weight, the sooner the string will break, right? Same with a car.... the bigger the weight (mass), the sooner the tires will reach their limit of traction. So, by reducing the mass at the rear of our car, we gained more rear grip.

[babyboss]

any downsides to having this battert in street car so far ?

[GaryS]

I remember something about a weight, like a lead bar or something, that BMW added in the rear of the car to get better front-rear balance. Is that true? If it is, did you remove it?

[Dackelone]

Why don't you race guys buy Porsche's race battery? It is like one or two pounds! Its about the size of a gold brick and priced about the same! It's at 2,000 euros! An option for the GT3-RS I believe.

[HP Autosport]

Originally Posted by babyboss

any downsides to having this battert in street car so far ?

No, no issues at all as long as you haven't add any other electronic consumers or like to sit and play your radio for hours.

[Evice]

This thread reminded me that I need to loose some weight My goal is 20 lbs. too.

[pixelblue]

this whole thing with less weight = more traction just doesn't cut mustard. yeah race cars are lighter but they add down force (lbs is the unit of measurement) in the form of rear wing to create more traction for cornering. hence, why 911 are known for their exceptional traction (engine hanging behind the wheels). you always want weight reduced up front (up to a certain point) and placed on the rear wheels. kind of surprised people who are actually racing here hypothesize this way. the 30 lbs lost can be compensated by raising the front of the car a bit so the weight is transfered backwards.

[endlesss]

What's the CCA rating on this battery?

[pixelblue]

^ you are stating the obvious. the statement was reducing weight from the rear adds to the traction and unless you would like to apply the laws of quantum physics here this logic just doesn't hold water. so if you don't compensate for the reduced weight but some sort of aerodynamics you will be just spinning your shinny looking wheels all over the place. capice?

[thez99]

All the technical shit aside, lets just ask one question..

Does this battery test well in our cars, racing or DD (not a "should be"), does it cause any fault codes, and is there merit to the argument about messin with the front/back weight ratio cuz im pretty damn sure removing weight from the rear could make it more floaty therefore leaving a lil less traction to those wheels. That and theres more weight to be removed from the front than the rear.

Who knows, I suppose if its under $200 for the harness and battery it might be worth it, could prob see a 3-4whp gain from this.

[Dackelone]

Originally Posted by thez99

Who knows, I suppose if its under $200 for the harness and battery it might be worth it, could prob see a 3-4whp gain from this.

lol....


Yea... 3-4 Hp gain from a battery! Yea... RIGHT! BS.

[pixelblue]

power/weight ratio gain would be less than 1/10th of a lb/hp but losing 30 pounds for $200 is still a good deal considering losing 60 lbs from the wheel/tire combo sets you back at least $2k and another $1-$2k for shedding 50-80 lbs for racing seats. as far as reliability, there was a thread somewhere on this forum and some people had complained about it running out of juice after a week of inactivity. could also be people didn't order the right size considering all their electronic options.

[MarkR171]

You don't gain horsepower by reducing weight...

[thez99]

Sry this wasnt a technical claim, it was more of how it would feel from the butt dyno so lets not chew this one up anymore k?

[The1]

for those talking porsches and pickup trucks. you have the right thoughts... but you're missing a few points.... pickup trucks with little wight on the back spin their tires in turns and have really really high centers of gravity, thus a horrible slip angle... especially if you put a plow on the front....

porsche, sort of the opposite scenerio. an extra amount of weight on the back adding straight line traction, but again the center of gravity combined with the extra weight, overwhelms the slip angle of the tires resulting in a very tail happy vehicle. the reason porsches NOW have so much grip when turning is because look at the size of the rear tires, and look how many years porsche have worked to get the balance correct. drive one from the 70s or 80s, go into a turn, and take your foot off the gas, you'll be going backwards into a tree.

removing weight from the back of these cars will result in the back end being more planted in turns especially with fairly wide tires. but your straight line acceleration shouldn't change much as it's a front rear drive setup, so when you accelerate, all the weight shifts onto the back tires anyhow.

I once took 30lbs out of the back seat of a subaru and about another 30lbs out of the trunk, and maybe 10lbs out of the engine bay. losing 30 lbs from a car alone is enough for me to notice in a car. I will likely be doing this in the future.

Car will feel tighter, more nippy, and more peppy.

i just wish i wasn't so tall, high center of gravity, and extra weight from having a lot of body. About 205lbs with a 32 inch waist. I might be able to lose about 15lbs at most on my body, but if i can take it out of the car rather then off myself i will.

Oh, and if you guys can keep your foot of the gas peddle with less weight in the car, you'll save gas and tire life. but seeing as these are turbo cars, we didn't buy them to save gas and tires.

[Evice]

Originally Posted by MarkR171

You don't gain horsepower by reducing weight...

Of course you don't gain HP, what you gain on is power to weight ratio , which is a better metric for cars. And I think the benchmark is there 8-9lbs/HP for uber sports cars, you try to hit, or below it.